1. Field of the Invention
The present invention relates to systems for testing spindles and axles of automotive vehicles.
2. Prior Art
In the prior art it has been known that the loading on automotive spindles and axles can be simulated by mechanical testing systems. For example, a triaxial loading fixture which utilizes bell cranks for compact loading arrangements is shown in U.S. Pat. No. 3,713,330. This system works well where sheet metal can be removed for testing the particular spindle or axle being utilized, but in particular when the type of system is used with "swing" arm axles, wherein upward movement of the axle or spindle relative to the vehicle causes the axis of the axle to move in fore and aft direction as well, the necessary compensations are quite complex, and while they can be carried out and accommodated, these movements give rise to programming and control problems.
A prior axle test unit, which was cited in U.S. Pat. No. 3,713,330, is described in the article by J. D. Camp, "Random Load Fatigue Tests On Automotive Components And Structures"--ASTM-STP-476, Pages 46-58, published June 1969. This article disclosed a direct loading device for loading in three separate loading directions on automotive spindles.
Other complex linkages have been utilized for loading spindles, including four bar linkages, and further independent cylinders have been used for providing brake load inputs, lateral inputs, longitudinal load inputs, and vertical inputs. However, the device of the present invention simplifies the mounting and control for the loading of axle spindles and includes means to apply brake forces.